Minutes of the 86th MTE meeting held on Thursday January 9th 2014

Present :

S. Burger, M. Giovannozzi, M. Hourican, S. Persichelli, B. Salvant, J. Vollaire.

Excused :

C. Hernalsteens.

 

1. A third round of impedance measurements have been performed this week following the failure of the sliding contact and the dismounting and rebuilding of the dummy septum. Short history of impedance measurements:

   • First measurement: November 2013. The first peak was found in agreement with numerical simulations. The second peak was not in good agreement. Nonetheless, it should not be relevant for beam dynamics as it is beyond the bunch spectrum.

   • Second measurement: December 2013. The first peak was found at higher frequency than in previous measurement. No attenuators were used. The position of the blade was not recorded. Following the measurement, some sliding contacts were found broken, but it was not clear the actual situation during the measurements. The BTV was not installed.

   • Third measurement: January 2014. The first peak is again in agreement with numerical simulations, while the second one was not and was at a different frequency than in the first measurement. Some differences in the measurement set-up were introduced, but this should not explain the shift in frequency of the second peak.

   • All in all, the current situation is considered to be very much the same as for the first measurement and the impedance measurement does not show any feature that prevents the installation of the TPS15.

   • All people involved in the impedance measurements and dummy septum dismantling and reassembly are warmly acknowledge for the swift actions!

2. TPS15 status and tests: 

   • Following the failure of the installed sliding contacts the dummy septum has be dismounted and reassembled. The issue has been traced back to a dimensional problem, which reduced the gap (1 mm, only) between the two parts to be put in contact. This has been fixed and current value of the distance is 3 mm. Mike is fully confident about the functionality of the sliding contacts in the present configuration.

   • The dummy septum is being pumped down following the completion of the impedance measurements.

   • All control tests have been performed with local control and the device passed all of them.

3. BTV status and tests:

   • All checks of the BTV movement have been completed as well as the final alignment of the screen. The fine tuning of the gas flow to control the IN position of the BTV should be performed in the coming days.

4. Overall schedule:

   • The installation date of MU14 is 13/1 and a couple of days are expected to be needed to perform the necessary actions before TPS15 can be installed. In particular, the positioning of the support blocks on the floor will require using the alignment target on MU14 and 15.

   • The current date for the installation activities of TPS15 is not earlier than 15/1.

5. Miscellaneous

   • The draft report is ready with only three missing contributions that should be made available very soon. All contributors are requested to give feedback on the edited contributions as well as on the authors' list and the acknowledgements. It would be good if this could be done by the beginning of next week (Action: All contributors).